• To provide information on thoracic anatomy and potential pathology for both skeletal and soft tissue structures.
• To allow a cardiological evaluation:
  • Evaluation of heart size.
  • Changes in chamber size.
  • Enlargement of blood vessels.
  • Changes to lung parenchyma/bronchi/pulmonary blood vessels.
• Thoracic radiography is indicated when a patient demonstrates:
  • Dyspnea.
  • Forced expiratory breathing.
  • Paradoxical respiratory movements.
  • Nasal discharge, eg bloody-foamy, severe serous or purulent, slight nasal discharge with generalized malaise.
  • Muffled heart sounds.
  • Non-specific respiratory signs.
  • Heart murmur.
  • Suspected thoracic effusion.
  • Gut sounds in the thorax.
  • Reflux/regurgitation.
  • Bilateral exophthalmos.
  • Suspected metastasis.

Uses

Advantages

• Quick.
• Simple to use.
• Standard equipment in most veterinary practices, therefore likely to be readily available.
• Relatively inexpensive.
• Requires minimal clinical experience.

Disadvantages

• 2D images only.
• Likely to miss minute detail in comparison to CT scanning.

Technical problems

• Poor technique and positioning.

Alternative techniques

• Other imaging modalities such as CT scanning, ultrasonography and endoscopy can be considered instead, or alongside thoracic radiography.
• Computed tomography.
• Ultrasonography.
• Endoscopy.

Time required

Preparation

• Having a list of suitable exposure factors for the species is recommended (exposure factor table). This should be available for various sizes of animals and is vital for allowing suitable radiographic imaging quality.

Procedure

• Dependent on the images required, however for a single dorsoventral and lateral view, 15-20 min is likely to be needed.
• Longer for repeat or additional views.

Decision taking

Risk assessment

• Standard practice radiography risk assessment and safety measures are needed:
  • Hands should never be placed in the primary beam.
  • Bodies of operators should be kept as far away as possible from the primary beam.
  • Sedation and general anesthesia are preferable to manual restraint.
  • If manual restraint is needed (moribund patient where sedation or anesthesia may be inappropriate), then the handler should be protected from scatter radiation. Consider placing the patient in a plastic box or gentle restraint with sandbags as well as horizontal beam radiography where appropriate.
  • Protective clothing should be considered if needed. All personnel involved should wear dosimeters.
• ALARA exposure principles should be applied at all times: the exposures that are used should be as low as reasonably achievable.
• Perform a risk assessment for the patient:
  • Disease status.
  • Is stabilization required prior to considering imaging.